(CNN) - The South is sweating through Memorial Day with temperatures hotter than an average summer day.
The region has been under a heat dome since Friday. That's when high pressure aloft acts like a lid trapping the heat below, setting the stage for potentially life-threatening conditions.
Some locations, such as Columbia, South Carolina, and Augusta, Georgia, are expected to reach record-breaking triple digital temperatures Monday.
New records could be set for high temperatures in several dozen cities, from Tennessee to Florida. Anyone who spends time outdoors today should keep hydrated, wear light-colored and loose-fitting clothing and try to stay in the shade.
Dozens of records have been set over the last few days, with records yesterday across much of the Carolinas and Georgia.
Daily records were broken in Atlanta this weekend when temperatures hit 94 degrees on Saturday and 95 degrees on Sunday. An all-time record May record was broken in Augusta when temperatures hit 101 degrees Sunday.
Columbia hit 100 degrees on Sunday.
Although it is not a record, it has reached that mark before Tucson, Arizona, where temperatures normally hit or surpass 100 earlier in the year. This is only the third time this has happened since the 1800s.
The West feels like early spring
As the eastern half of the country bakes this weekend, the western half will feel more like early spring. After one of its latest heavy snows on record, Denver's temperatures have finally climbed back to average. But farther west, temperatures remain far below average.
Las Vegas; Phoenix; Reno, Nevada; and Fresno, California will be 20 to 25 degrees below normal. Las Vegas is expected to have a high temperature Monday of only 70 degrees, which is its average for March 15.
Phoenix is expected to have a high temperature of 79 degrees on Memorial Day, its average high for March 25.
Not to mention, it is expected to snow at the Grand Canyon.
CNN Meteorologists Allison Chinchar and Dave Hennen contributed to this report
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